CD274 and osteosarcoma: By comparing the therapeutic effects of 27 patients with osteosarcoma before and after treatment, neoadjuvant chemotherapy was related to an the increase in the density of CD8+ T cells, CD3+ T cells, Ki67+CD8+ T cells and PD-L1+ immune cells, and the myeloid suppressor cells of HLA-DR-CD33+ decreased significantly after treatment [89].